FDA Approves Valtrex Caplets for Reducing Risk of Spreading Genital Herpes

RESEARCH TRIANGLE PARK, N.C. -- GlaxoSmithKline (GSK) announced today that the U.S. Food and Drug Administration (FDA) has approved a supplemental new drug application (sNDA) for Valtrex (valacyclovir HCl) caplets for suppressive therapy in otherwise healthy adults with genital herpes in order to reduce the risk of heterosexual transmission of genital herpes (GH).

The study of 1,484 couples conducted in support of the application showed that once-daily suppressive therapy with Valtrex, in addition to counseling on safer sex practices, reduced the risk of transmission of symptomatic genital herpes (signs or symptoms of GH) by 75 percent and reduced the risk of overall acquisition of the virus by 48 percent. Safer sex practices should always be used with suppressive therapy.

"As a physician who's been treating patients suffering with herpes for years, I have consistently heard from my patients that fear of giving this disease to their partner is a major concern. This approval gives patients another tool, in addition to safer sex practices, to help them protect their partners," said Larry Corey, MD, lead study investigator and professor, Laboratory Medicine and Medicine, University of Washington and head of the Program in Infectious Diseases, Fred Hutchinson Cancer Research Center. "Now, in addition to safer sex practices, patients with herpes can take once-daily Valtrex to reduce their own outbreaks and, at the same time, protect their partner."

While genital herpes is not a life-threatening disease, once infected, the virus never leaves the body, making it a lifelong condition that can recur at various times with or without symptoms. The virus is generally spread through skin-to-skin contact during sexual activity and often during times when there are no visible signs of a herpes outbreak. In fact, in clinical studies, the majority of people got GH from a partner who knew they had GH but reported no signs or symptoms at the time of recent sexual activity.

"When you're diagnosed with a lifelong disease like herpes, you have so many questions and concerns, including how is it going to affect my relationship and how can I avoid spreading it to my husband," said Cecilia McCracken, a genital herpes sufferer who participated in the study. "However, with this approval today, my husband and I both have more comfort knowing we're doing what we can to reduce the risk."

The approval follows a unanimous (13-0) recommendation by an FDA Advisory Committee on May 14, 2003, to approve suppressive therapy with Valtrex for reducing the risk of transmission of genital herpes in otherwise healthy, heterosexual individuals.

"The study was a landmark study in herpes research. GlaxoSmithKline acknowledges the patients and investigators who diligently participated in this very demanding and unique study. We are very pleased by this approval and what this additional benefit can mean to millions of herpes sufferers and their partners," said Clarence L. Young, MD, vice president of clinical development and medical affairs for GlaxoSmithKline.

The study was conducted in 1,484 healthy, heterosexual, monogamous couples. The primary endpoint of the study in support of the sNDA was to reduce the risk of transmission of symptomatic genital herpes (signs or symptoms of GH confirmed with a lab test) to the uninfected partner. The study showed that once-daily suppressive therapy with Valtrex 500 mg caplets reduced the risk of transmission of symptomatic genital herpes by 75 percent versus placebo (0.5 percent on Valtrex vs 2.2 percent on placebo). In addition, suppressive therapy with Valtrex reduced the risk of overall acquisition of the virus (with or without symptoms confirmed with a lab test) by 48 percent versus placebo (1.9 percent on Valtrex vs. 3.6 percent on placebo).

Throughout the eight-month study, all couples were counseled on safer sex practices at all study visits and encouraged to use condoms. The principles of safer sex practices were (1) to avoid sexual contact when the infected partner had any symptoms of genital herpes and (2) consistent and correct use of condoms during all sexual contacts. In addition, Valtrex significantly reduced the number of recurrences in the infected partner versus placebo, consistent with previous studies.

The most commonly reported side effects in the study were headache (Valtrex 29 percent, placebo 26 percent), nasopharyngitis (Valtrex 16 percent, placebo 15 percent), and upper respiratory infection (Valtrex 9 percent, placebo 10 percent). The effect of Valtrex on transmission of genital herpes has not been established in immunocompromised individuals or same-sex couples. The effect of Valtrex on reducing transmission beyond eight months has not been established.

In 1991, an estimated 45 million, or 1 in 5, Americans were infected with the virus that causes genital herpes. Experts estimate that now 60 million Americans could have genital herpes. However, as many as nine out of ten of those are unaware they have genital herpes and may only have experienced a mild initial outbreak without recognizing recurring symptoms of the disease. Symptoms of genital herpes may include painful or itchy clusters of blisters, bumps and rashes in the genital area, or on the thighs or buttocks. Many people confuse genital herpes symptoms with other conditions such as urinary tract infections (UTIs), ingrown hair, jock itch, zipper burn, allergic reactions, vaginal infections, a cut or a scratch, or irritation from sexual intercourse or tight jeans. Though the disease is most contagious during an outbreak, it can also be contagious between outbreaks when no signs and symptoms are present. In fact, in clinical studies, the majority of people got GH from a partner who knew they had GH but reported no signs or symptoms at the time of recent sexual activity.

Source: GlaxoSmithKline